EP2563630A1

EP2563630A1 - Braking system for motor vehicles

Info

Publication number: EP2563630A1
Application number: EP11715529A
Authority: EP
Inventors: Hans-Jörg Feigel
Original assignee: Continental Teves AG and Co OHG
Current assignee: Continental Teves AG and Co OHG
Priority date: 2010-04-30
Filing date: 2011-04-19
Publication date: 2013-03-06
Anticipated expiration: 2031-04-19
Also published as: CN102869552A; EP2563630B1; CN102869552B; WO2011134841A1; US9174617B2; US20130043718A1; DE102011007353A1

Abstract

Braking system for motor vehicles having a brake pedal (1), a travel simulator (2) which is coupled to the brake pedal (1) via a first mechanical connecting means (8) which transmits actuating forces, a brake master cylinder (3) which has at least one pressure chamber (5) and one piston (4), and the pressure chamber (5) of which is connected or can be connected via a pressure line (7) to at least one hydraulically actuable wheel brake (10), and an electrically controllable electromechanical drive device (6), by way of which the piston (4) of the brake master cylinder (3) can be actuated via a second mechanical connecting means (9), wherein the electromechanical drive device (6) is arranged between the brake pedal (1) on one side and the brake master cylinder (3) and the travel simulator (2) on the other side, and wherein the first mechanical connecting means (8) extends from the brake pedal (1) through the drive device (6) to the travel simulator (2).

Description

Brake system for motor vehicles

The invention relates to a brake system for motor vehicles according to the preamble of claim 1.

In automotive engineering, "brake-by-wire" brake systems are becoming increasingly widespread

Brake systems, the brake on the one hand without active involvement of the driver due to electronic signals "foreign" - are operated. These electronic signals can be output, for example, from an electronic stability program ESC or a distance control system ACC. On the other hand, can be dispensed with an actuation of the brake system completely or partially, when requested by the vehicle driver via a brake pedal operating force Bremswir ^¬ effect is achieved, for example, by switching an electric vehicle drive in a generator mode. In ^¬ cases, the operating state of the brake does not correspond to the braking action requested by the driver.

From WO 2006/111392 AI a brake system with a brake pedal, which is operatively connected to a Wegsimulatorfeder, and an electric motor drive device known, wherein the drive device comprises an electric motor and a transmission and adjusts a piston of a piston-cylinder system, so that in the working space of the Zylin ^¬ DERS, which is connected via a pressure line with a wheel brake, a pressure setting. The electric motor or the transmission of the drive device is parallel to arranged the piston of the piston-cylinder system, that is, the drive device is arranged around the piston-cylinder system. This causes a short length of the piston motor unit, however, the corresponding complex training of the transmission ^¬ , eg the specially designed toothed rack ^¬ ge of the transmission, perceived as disadvantageous.

The present invention has for its object, ^{bereitzustel ¬} len an alternative brake system with a simpler structure.

This object is inventively achieved by a braking system ge ^¬ Mäss claim. 1

The invention is based on the idea that the electromechanical drive device between the brake pedal and the master brake cylinder as well as between the brake pedal and the travel simulator is arranged, and that the first mechanical connection means extends from the brake pedal by the Antriebsvor ^¬ direction through to the travel simulator.

One advantage of the inventive brake system is the simp ^¬ che building with nevertheless compact construction. Thus, by the sequential arrangement of the drive device and the master cylinder a little expensive execution of the second mechanical connection between the drive device and the master cylinder is possible. Another advantage is that a guide of the first mechanical connection means in the drive device is easy to implement.

Preferably, the brake system in a "brake-by-wire" - operating mode is controlled both by the driver and independently of the driver, preferably the brake system is operated in the "brake-by-wire" mode and can in a ner fallback mode are operated in the only operation by the driver is possible.

The brake system according to the invention comprises a travel simulator, which is coupled to the brake pedal via a first me ^¬ chanical connection means transmitting actuating forces. The travel simulator provides the vehicle operator in a 'brake-by-wire "a pleasant brake pedal feel and advantageously comprises at least one elastic ele ment ^¬. More preferably, the effect of the travel simulator can be deactivated, in particular in a fallback mode of operation.

Preferably, one of the mechanical connecting means is at ^¬ least partially formed as a hollow body and the other mechanical connecting means extending at least in part, by these ^¬ hollow body. As a result, a mechanical guidance of the other connection means is achieved. In addition to the ^¬ the relative movement of the two connecting means can be so easily measured and monitored. More preferably, the second mechanical coupling means is at least partially hollow and ^¬ as the first mechanical connection ^¬ means extends at least partially within the second me chanical ^¬ connecting means.

The displacement simulator preferably comprises at least one piston-cylinder arrangement whose simulator piston is connected to the first mechanical connection means. The Simulatorkol ^¬ ben is advantageously performed in the cylinder of the piston-cylinder arrangement displaceable and cooperates with an elastic element, which gives the driver a pleasant brake pedal feel. Particularly preferably, the travel simulator comprises at least one hydraulic piston-cylinder arrangement with a hydraulic space. According to a particularly advantageous embodiment of the invention, the hydraulic space of the travel simulator with at least ^¬ a wheel brake, for example via the master cylinder and / or via a valve connected or connectable. The way simulator can serve as a filling device for pre-filling the wheel brakes.

Advantageously, the travel simulator comprises at least one hydraulic piston-cylinder arrangement with a hydraulic chamber, wherein the hydraulic chamber is connected via an electrically controllable, eg normally open, valve with a pressure ^¬ medium container. The travel simulator can be switched off and on by closing and opening the valve.

The displacement simulator preferably comprises in addition to the simulator piston another piston and a spring, the Si mulatorkolben have a smaller piston effective area than the other piston, in which further piston is displaceably guided and supported by means of the spring on the further piston from ^¬ . This results in a Springer function is achieved when the brake pedal ^¬ activity.

In order to prevent repercussions on the brake pedal in an anti-lock control is preferably arranged between the hydraulic space of the travel simulator and the wheel brake an electrically controllable, normally open isolation valve ^¬ .

According to another advantageous development of the Erfindun the hydraulic chamber of the travel simulator via a return is ^¬ valve with the brake master cylinder and connected to a wheel brake. According to a development of the brake system according to the invention, the displacement simulator and the master brake cylinder are arranged substantially parallel to each other and at least the ers ^¬ te or the second mechanical connection means comprises a Kraftumlenkmittel. This will he aims ^¬ a short overall length.

According to a preferred embodiment of the brake system, the piston-cylinder arrangement of the travel simulator coaxial with the first mechanical connection means, and particularly preferably ^¬ coaxially arranged to the drive device, and the second mechanical connection means comprises a Kraftum ^¬ steering means.

According to another preferred embodiment of the

Master cylinder arranged coaxially with the second mechanical connection means, and more preferably coaxially to the Ant ^¬ rubbing device, and the first mechanical Ver ^{¬ connecting means} comprises a Kraftumlenkmittel.

The travel simulator preferably comprises two piston-cylinder arrangements whose simulator pistons can be actuated jointly by the first mechanical connection means. The two piston-cylinder arrangements are advantageously symmet ^¬ risch and each angeord ^¬ net parallel to the master cylinder.

The electromechanical drive device preferably comprises an electric motor and a transmission device, wherein the transmission device is in operative connection with the second mechanical connection means. Particularly preferably, the transmission device is designed as a ball screw. According to a development of the brake system according to the invention, the first and second mechanical coupling means are formed such that actuation of the Hauptbremszylin ^¬ DERS in brake actuating direction by means of the first mechanical connecting means by a mechanical contact Zvi ^¬ rule the first mechanical connecting means and the

Master cylinder or by a mechanical contact between the first mechanical connection means and the second mechanical connection means is possible. As a result, a braking operation by the driver in the fallback mode is possible if, for example, the power supply of the drive device has failed. In the 'brake-by-wire "mode, the mechanical contact between ers ^¬ tem mechanical connecting means and the master cylinder and the second mechanical connection means vorteilhafterwei ^¬ se is to be prevented in order to prevent a reaction on the brake pedal. If, in the unactuated state of the braking system, therefore, Advantageously, a predetermined mechanical gap between the first mechanical connection means and the master brake cylinder or the second mechanical connection means The mechanical connection means only comes into mechanical connection after overcoming this predetermined distance (gap) with the master brake cylinder or second mechanical connection means.

The brake system according to the invention preferably comprises at least one sensor device by means of which the relative position of first to second mechanical connection means is determined. As a result, an inadvertent mechanical contact between the first mechanical connection means and

Master cylinder or second mechanical connection means are detected and, where appropriate measures for Verhinde ^¬ tion of the contact can be initiated. In order to prevent mechanical contact between the first mechanical connection means and the master brake cylinder or between the first mechanical connection means and the second mechanical connection means, for example in a brake pressure reduction in an anti-lock control, is advantageously the pressure chamber of the master cylinder via an electrically controllable valve with a pressure medium container connectable, so that in predetermined situations, a discharge of brake fluid from the master cylinder is possible in the pressure fluid container.

Preferably, the piston of the master cylinder by means of the first mechanical connection means is also operable when the drive device is blocked. To this end, the second mechanical connection means is particularly preferably formed ^¬ two pieces. Alternatively, it is particularly preferred that the coupling between the piston of the master cylinder and the second mechanical connection means is made detachable.

The first mechanical connection means and the second me ^{¬-mechanical} connection means are advantageously designed and arranged such that the second mechanical Ver ^¬ binding agent can be adjusted by the drive device along a predetermined path in the brake actuating direction relative to the first mechanical connection means, without any entrainment or reaction on the brake pedal he follows ^¬ . For this purpose, for example, an opening is provided in the mechanical connecting means designed as a hollow body.

For brake pressure modulation preferably electrically controllable, normally open valves are arranged in the brake lines to the wheel brakes. A brake pressure modulation is carried out by means of the drive device in a multiplex process. For an accelerated reduction in brake pressure in a wheel brake a wheel brake or wheel brake circuit via an electrically controllable, normally closed Ven ^¬ valve with a pressure medium container is particularly preferably connectable.

Further preferred embodiments of the invention will become apparent from the subclaims and the following description with reference to figures.

It show schematically

1 shows a first embodiment of a erfindungsge ^¬ MAESSEN brake system,

2 shows a second embodiment of a erfindungsge ^¬ MAESSEN brake system,

3 shows a third embodiment of a erfindungsge ^¬ MAESSEN brake system,

4 shows a fourth embodiment of a erfindungsge ^¬ MAESSEN brake system,

5 shows a fifth embodiment of a erfindungsge ^¬ MAESSEN brake system,

6 shows a sixth embodiment of a fiction, ^¬ brake system,

7 shows a seventh embodiment of a erfindungsge ^¬ MAESSEN brake system, 8 shows a detail of an eighth embodiment of a brake system according to the invention,

9 shows a ninth embodiment of a erfindungsge ^¬ MAESSEN brake system, and

10 shows a tenth embodiment of a erfindungsge ^¬ MAESSEN brake system.

Corresponding components are provided in all figures with the same reference numerals.

In Fig. 1, a first embodiment of an inventive brake system ^{¬ is} shown schematically. The brake ^¬ system includes a brake pedal 1, which is coupled via a supply ^¬ Actuate the power-transmitting first mechanical Verbindungsmit ^¬ tel 8 with a pedal feeling simulator (travel simulator). 2 By way of example, the first mechanical connection 8 is designed as a push rod which connects the brake pedal 1 to the travel simulator 2. The pedal feel simulator 2 comprises at least one elastic element, for example a spring 30, and is intended to give the driver a pleasant brake pedal ^feel . Furthermore, the brake system comprises a master cylinder 3, in which at least one pressure piston 4 is displaceably guided, wherein the piston 4 with the main ^¬ brake cylinder 3 defines a pressure chamber 5 for generating a hydraulic brake pressure. Pressure chamber 5 of the master brake ^¬ cylinder 3 is connected by means of brake line 7 with hydraulically operable ^¬ wheel brakes 10. Furthermore, the

Brake system an electrically controllable drive device 6 for generating a foreign force for actuating the wheel brakes 10. For this purpose, the pressure piston 4 via a second mechanical connection means 9 of the electromechanical Fremdkraftak- tuator 6 can be actuated. Via the second mechanical connection 9 Actuator 6 can exert a force on the pressure piston 4 for actuating the master cylinder 3. Actuator 6 can be controlled in accordance with a brake pedal operation.

Drive device 6 is arranged between the brake pedal 1 and the master cylinder 3 and between the brake pedal 1 and the travel simulator 2. Accordingly, brake pedal 1 are ei ^¬ hand, and travel simulator 2 and the master brake cylinder 3 on the other on opposite sides of the actuator 6 angeord ^¬ net. The first mechanical connection 8 passes through the actuator 6 accordingly.

Path simulator 2 includes, for example according to a piston-cylinder arrangement, the simulator piston 31 is guided displaceably in cylinder 33. Simulator piston 31 and cylinder 33 define a space 32 in which spring 30 is arranged, via which simulator piston 31 is supported on cylinder 33. Simulator piston 31 is fixedly connected to the first mechanical connection means 8.

Displacement simulator 2 and master cylinder 3 are spaced from each other, arranged substantially parallel to the axis side by side. In this case, for example, pedal feel simulator 2 is arranged coaxially with the first mechanical link 8 which is being formed (e.g., as a push rod) (axial alignment of first mechanical linkage 8 and path simulator 2). The second mechanical connecting means 9 comprises a force deflection in order to be able to transmit the force applied by the drive device 6 to the master brake cylinder 3, which is offset radially relative to the displacement simulator 2.

The second mechanical connecting means 9 is designed in a Be ^¬ rich in and near the actuator 6 as a hollow body, for example as a cylindrical sleeve, and the first mechanical Ver Binding means 8 is piecewise arranged within the hollow body ^¬ . The second mechanical connection 9 has, for example in the region of the force deflection, an opening region in the direction of the displacement simulator 2, on which the first mechanical connection 8 emerges from the interior of the hollow body.

2, a second embodiment of an inventive brake system ^{¬ is} shown schematically. The brake ^¬ plant comprises as the first embodiment, a Bremspe ^¬ dal 1 which is coupled via a first mechanical connection 8 with a travel simulator 2, a master cylinder 3 with the piston 4 and the pressure chamber 5, are connected to which wheel brakes 10, and an electrically controllable Ant ^¬ rubbing device (actuator) 6, which is coupled or coupled via a second mechanical connection 9 with the pressure piston 4. Brake pedal 1 on the one hand and travel simulator 2 and master cylinder 3 on the other hand are arranged on opposite sides of the actuator 6, wherein the displacement simulator 2 and master cylinder 3 are arranged side by side. The first mechanical connection 8 extends through the actuator 6.

According to the second embodiment, the second mechanical ^¬ specific connecting means 9 is substantially formed as a cylindrical hollow body and the master cylinder 3 is disposed coaxially with the second mechanical connection means 9

(axial alignment of second mechanical connecting means 9 and master cylinder 3). The first mechanical connection Ver ^¬ 8 comprises a force deflection in order to transfer the Bremspedalbetä ^¬ allowance in relation to the radially offset to the master cylinder 3 mounted travel simulator. 2

The first mechanical connection 8 extends at least in part ^¬ example 9. connecting means 9 within the hollow body of the second means of Verbindungsmit ^¬ has an opening area perpendicular to the direction of the master cylinder axis / second mechanical connection, in which the first mechanical connection 8 emerges from the interior of the hollow body.

Both in the first and in the second embodiment, the first 8 and the second 9 mechanical connection are formed such that upon a displacement of the first mechanical connection 8 relative to the second mechanical connection 9 (in the direction of a brake operation), which reaches a predetermined amount (distance d is overcome), the first mechanical connection 8 mechanically engages the second mechanical connection 9 or the piston 4, so that the force acting on the first mechanical connection 8 from a brake pedal operation is transmitted to the master cylinder 3. In this way, if, for example, an actuation of the master cylinder 3 by the Fremdkraftaktuator 6 we ^¬ gen a failure of the power supply of Fremdkraftaktua- sector 6 is not possible in one mode of Bremsanla ^¬ ge (so-called mechanical fallback mode) a ^{¬ handle} a brake pedal actuation on the Master brake cylinder 3 take place.

Example In accordance with this, according to the first Ausführungsbei ^¬ game (Fig. 1) is disposed on the first mechanical connecting means 8 is a formation 11 which is engageable with a arranged on the two ^¬ th mechanical connecting means 9 stop 12, so that the operating force of the first mechanical connection 8 is transmitted to the second mechanical connection 9 and so on the master cylinder 3.

According to the second embodiment shown in FIG. 2, the first mechanical connection 8 in the region of the force deflection (when reaching the end of the opening in the second mechanical connection 9) come into contact with the pressure piston 4, ie piston 4 forms a stop 12 for the connection 8. Accordingly, the actuation force in the me ^¬ chanic fallback mode of the first mechanical connection 8 can be transmitted directly to the master cylinder 3.

According to the first and second embodiments, the second mechanical connection 9 in the region of the actuator 6 is fixedly connected thereto, i. in the case of blocking of the actuator 6, the second mechanical connection 9 is prevented by actuator 6 from moving.

Thus, in the case of a blocked actuator 6, the force acting on the brake pedal 1 in the fallback plane via the first mechanical connection 8 can be transmitted to the master cylinder 3, the second mechanical connection 9 according to the first embodiment (Fig. The first part of the second mechanical connection 9, which is fixedly connected to the actuator 6, is prevented by the actuator 6 from moving, whereas the second part of the second mechanical connection 9, which is fixedly connected to the piston 4, via the molding 11th the first mechanical connection 8 can be moved in the direction of the master cylinder 3. By way of example, the second mechanical connection 9 is divided into two parts in the region of the stop 12. The stop 12 is arranged on the second part of the second mechanical connection 9.

In order to enable transmission of the brake pedal force via the first mechanical connection 8 to the master brake cylinder 3 in the fallback mode when the actuator 6 is blocked, according to the second embodiment shown in FIG the second mechanical connection 9 is integrally formed and firmly connected to the actuator 6, but not firmly connected to the piston 4. Accordingly, the piston 4 can be actuated by the first mecha ^¬ African compound 8 in the brake actuation direction, with the piston 4 away from compound 9.

According to the exemplary embodiments (eg, FIGS. 1 and 2), the pressure chamber 5 of the master brake cylinder 3 can be connected to a pressure medium container 14 via an electrically controllable, eg normally closed, outlet valve 15. Pressure medium tank 14 has a low pressure level and is designed, for example, as a low-pressure accumulator or a pressure medium reservoir (atmospheric pressure). The operation of the outlet ^¬ valve 15 will be explained below.

The operation of the brake system according to the invention is explained in more detail below with reference to the embodiments shown in FIGS. 1 and 2. In an application during the loading ^¬ triebsart 'brake-by-wire "operating the Bremspe ^¬ dals 1 leads to a movement of the first mechanical connection 8 and to the displacement of the simulator piston 31 of the Wegsimula ^¬ gate 2. The brake pedal operation is (by a sensor The electromechanical actuator 6 is actuated in accordance with the detected brake pedal actuation and thus actuates the pressure piston 4 in accordance with the brake pedal actuation via the second mechanical connection 9, which leads to a buildup of brake pressure in the wheel brakes 10. If the driver is away from the brake pedal 1, then the first mechanical connection 8 and the piston 31 of the Pedalgefühlsi ^¬ mulators 2 moves against the brake operating direction. actuator 6 is controlled accordingly so that the pressure piston 4 can recede ^¬ degraded (opposite to the brake operation direction) and the brake pressure in the wheel brakes 10 corresponding to the brake pedal operation In a similar shift Thus, there is no contact with stop 12 of the first 8 and second 9 mechanical connecting means.

Even if the brake pedal 1 is not actuated, the master cylinder 3 can be actuated via the second mechanical connection 9 of the actuator 6. This is necessary in case of ak ^¬ tive braking action by a driving dynamics control function or a distance control function. In order to prevent a reaction on the brake pedal 1 in this case, the first 8 and the second 9 mechanical connection, eg bezüg ^¬ Lich lengths and relative arrangement of force deflection, opening area, etc., are formed such that a displacement of the second mechanical connection (in the brake operating direction) is possible relative to the first mechanical connection 8 over a predetermined length 13, without resulting in a force-transmitting connection (a stop) and thus to a reaction to the brake pedal 1.

According to the example shown in Fig. 1 first embodiment, the second mechanical connection 9 can be moved along the length 13 in the brake actuating direction before the second mechanical connection 9 is in the opening area with the simulator piston 31 of the travel simulator 2 in contact and in egg ^¬ ner further movement Entrainment of the simulator piston 31 causes, which leads to a reaction to the brake pedal 1.

According to the second embodiment shown in Fig. 2, the second mechanical connection 9 can be moved over the length 13 in the brake actuation direction before the second mechanical connection 9 comes with the brake pedal 1 facing the end of the opening portion with the first mechanical connection 8 in contact. In another movement the second mechanical connection 9, a driving of the first mechanical connection 8 is effected in the brake actuation direction, which leads to an entrainment of the brake pedal 1.

When the brake pressure in the wheel brakes 10, for example in an anti-lock control, below the brake pressure level, which corresponds to the brake pedal operation by the driver to be reduced, the second mechanical connection 9 is moved by the actuator 6 against the brake actuation direction. If the brake pedal operation by the driver and thus the position of the first mechanical connection 8 remains unchanged, it may come to a contact on the stop 12, ie there would be a force on the first mechanical connection 8. Such a reaction would be for the driver on the brake pedal 1 felt and would be distracting. To prevent this, an approach of the stop 12 to the first mechanical connection 8, 11 is advantageously based on a sensor device 34, which the position / position of a component of the path simulator 2 (eg the piston 31) or the position / position of the first mechanical connection 8 detected, and a sensor device 35, which detects the La ^¬ ge / position of a component of the actuator 6, and thus the second mechanical connection 9, or the piston 4 of the master cylinder 3, detected and monitored. Below ^¬ the distance between the stop 12 and the first mecha ^¬ African compound 8, 11 a threshold, the normally closed valve 15 is opened and thus Druckkam ^¬ mer 5 of the master cylinder 3 is connected to pressure fluid reservoir 14, whereby a reduction of the system pressure, and thus possibly in the wheel brakes 10, is achieved. Further return of the second mechanical connection 9 against the brake actuation direction by the actuator 6 is then no longer necessary. The brake system according to the invention is advantageously used in motor vehicles, which are braked by means of generator operation of the electric drive motor (also active ^¬ neratives braking or regenerative braking referred to). In a Rekuperationsbremsung the friction brakes 10 should not be or possibly only ^¬ supportive in order to achieve the highest possible energy yield of the recuperation. Accordingly, in a Rekuperationsbremsung a brake pedal operation by the driver (ie, a shift of the first mechanical connection 8, 11 in the brake actuation direction) should not lead to a (significant) brake pressure build-up in the wheel brakes 10. In a Rekuperationsbremsung the normally closed valve 15 can therefore be opened in the brake systems according to the invention and the pressure chamber 5 of the master cylinder 3 with Druckmittelbehäl ^¬ ter 14 are connected, so in the case of actuation of the master cylinder 3 by the first mechanical connec ^¬ tion means (stop 12) Pressure fluid can flow into the Druckmit ^¬ telbehälter 14. In addition, actuator 6 may be controlled to actuate 9 master cylinder 3 via the second mechanical connection ^¬ medium. Thus, engagement of the first mechanical connection means 8, 11 with the stop 12 is prevented and yet no brake pressure is built up on the wheel brakes 10. A critical approach of the first mechanical connection 8, 11 to the stop 12 can, as already explained above, be recognized on the basis of the sensor devices 34, 35.

Displacement simulator 2 is advantageously switched off ausgebil ^¬ det. For example, path simulator 2 and its shutdown is designed such that in case of failure of the brake system, for example in a power failure, no or low power loss remains effective. In Fig. 3, a third embodiment of an inventions ^{¬ to the} invention brake system is shown schematically. As in the second embodiment, the second mechanical Ver ^{¬ connecting means} 9 is designed substantially as a cylindrical hollow body and master cylinder 3 is arranged coaxially to the two ^¬ th mechanical connecting means 9. The first mechanical connection 8 comprises a force deflection in order to be able to transmit the brake pedal actuation to the path simulator 2 arranged offset radially to the master brake cylinder 3, and extends at least partially within the hollow body of the second connection means 9 and extends through actuator 6. In contrast to the second Ausführungsbei ^¬ game the displacement simulator 2 is performed hydraulically according to the third embodiment. Displacement simulator 2 comprises a piston-cylinder arrangement whose simulator piston 31 is displaceably guided in cylinder 33 and which comprises a hydraulic space 32 ^λ . Simulator piston 31 is actuated by the first mechanical connection means 8 and fixedly connected thereto. Optional travel simulator 2 comprising a further Simu ^¬ latoranordnung 36 which is hydraulically connected to the hydraulic chamber 32 ^λ of the piston-cylinder assembly 31., 33

The hydraulic space 32 ^{λ of} the travel simulator 2 is connected via an electrically controllable, eg normally open, valve 16 with a pressure medium tank 14 to allow a shutdown of the simulator 2 (eg in the Rückfallbe ^¬ mode of operation). The pressure medium container 14 is executed, for example, as a low-pressure accumulator, but may also be designed as a pressure medium reservoir. To reduce the hydraulic components of the brake system advantageously the hydraulic space 32 ^{λ of} the travel simulator 2 so ^¬ as the pressure chamber 5 of the master cylinder 3 with the same pressure medium container 14 can be connected, as shown in FIG. men is. However, it can also be two pressure fluid containers.

In normal operation of the brake system (operating mode "brake-by-wire") valve 16 is closed (energized according to the example) and the hydraulic space 32 ^{λ of} the simulator 2 is separated from the pressure ^¬ medium container 14.

Preferably, the brake master cylinder 3 of the brake system is designed such that with a pedal actuation force of 500N, a vehicle deceleration of at least 0.5 g (g: acceleration due to gravity) can be achieved.

In order to achieve, for example in the above-described design of the brake system, a vehicle deceleration perceptible to the driver in the case of small pedal paths, the brake system advantageously comprises a filling device with which a pre-filling of the wheel brakes 10 can be carried out. The filling device comprises, for example, a cylinder-piston arrangement with a hydraulic chamber whose piston can be actuated by the first mechanical connection 8. The hydraulic space of the filling device is connected to the wheel brakes 10 or the pressure chamber 5 of the master cylinder 3. By means of the Füllein ^¬ direction the wheel brakes can be filled 10 up to a predetermined pressure. The predetermined pressure is adjustable / specifiable eg by a pressure relief valve or by the bias of a low-pressure accumulator spring. Upon actuation of the brake pedal 1, the piston of the filling device is actuated by the first mechanical connection 8 and so the wheel brakes 10 filled from the filling until a predetermined by the pressure relief valve or the bias of Fe ^¬ the low pressure accumulator pressure value is reached. According to the third embodiment of FIG. 3, the displacement simulator 2 or its cylinder-piston arrangement 31, 32 33 is used as a filling device. For this purpose, the hydraulic chamber 32 ^{λ of} the path simulator 2 via a check valve 17 to the master cylinder 3 and thus the wheel brakes 10 is connected. The bias of the spring of the low-pressure accumulator 14 limits the filling pressure.

4, a fourth embodiment of an inventive brake system ^{¬ is} shown schematically, in which the master cylinder is designed as a tandem master cylinder 3 (in axial construction). The primary piston 4 of the tandem master cylinder 3 is actuated by the electromechanical Fremdkraftak- tuator 6 via the second mechanical connection means 9. According to the example, the primary piston circuit I and the floating ^piston circuit II are each connected to two wheel brakes 10. For brake pressure modulation is in the brake lines 7 to the wheel brakes 10, an electrically controllable, eg normally open, valve 18 per wheel brake 10 ordered to ^¬ . A brake pressure modulation can be carried out by means of the (re- versierenden) actuator 6 in a multiplex process. The other components of the brake system and their arrangement essentially correspond to those of the third embodiment.

In Fig. 5 is a fifth embodiment of a brake system according OF INVENTION ^¬ dung with a tandem master cylinder 3a, schematically shown with an open structure 3b. ^¬ way simulator 2 is arranged coaxially with first mechanical connecting means. 8 The tandem master cylinder 3 comprises two cylinder-piston assemblies, wherein the cylinder-piston assembly 3a of the primary piston circuit is formed parallel to the cylinder-piston assembly 3b of the floating piston circle. The pressure piston 4 of the cylinder-piston assembly 3a is (about the mechanical connection means 9) mechanically coupled to the Ant ^¬ rubbing device 6 and the piston 40 of the cylinder-piston assembly 3b is hydraulically coupled via a line 41 to the piston. 4 Both cylinder-piston assemblies 3a, 3b are arranged parallel to the travel simulator 2, wherein the Zy ^¬ cylinder-piston assemblies 3a, 3b are arranged on opposite sides of the travel simulator 2. The second mechanical ^¬ specific compound 9 is advantageously designed in such a way that the piston 40 of the floating piston circle 9 can be betae ^¬ Untitled mechanically by means of the second mechanical connecting means (eg, in case of failure of the primary piston circle).

According to the example, the piston 40 of the floating piston circuit is actuated only from a predetermined displacement of the second mechanical connection 9 in the brake actuation direction.

For this purpose, a mechanical gap between the second mechanical ^¬ African connection 9 and the pressure piston 40 of floating piston circuit available, which must be overcome, be ^¬ before the second mechanical connection 9 engages with a part connected to the pressure piston 40 extension 42 engages.

The remaining components of the brake system according to the fifth embodiment, their arrangement and operation has already been explained in connection with FIGS. 1 to 4.

Fig. 6 shows a sixth embodiment of an inventive ^¬ brake system. Again, the master cylinder 3 is designed as a tandem master cylinder in dissolved construction. In contrast to the fifth Ausführungsbei ^¬ game the primary piston circuit and the floating piston circuit are each formed by two cylinder-piston assemblies 3a and 3b, wherein the piston surface of a piston in each case half is large as piston area of the corresponding pressure piston per circle of the fifth embodiment. The pressure chambers of the two cylinder-piston assemblies of a circle are connected to each other via a hydraulic line (eg line 43 for cylinder-piston assemblies 3a).

The two cylinder-piston assemblies 3a and 3b of a circle I and II are respectively arranged parallel to the displacement simulator 2, on opposite sides of the displacement simulator 2 and symmetrical to the axis of the first mechanical connection means 8 ^¬ . This division into two cylinder-piston arrangements (each circle) and their symmetrical arrangement allows torque-free force introduction by the actuator 6. Beispielsgemäß the two piston assemblies 3b of the floating piston circuit are rotated by 90 degrees against each other angeord the two piston assemblies 3a of the primary piston circuit ^¬ net. Therefore, in Fig. 6, only the primary piston circuit (piston assemblies 3a) shown, the piston assemblies 3b are arranged rotated by 90 degrees and the sake of clarity ^¬ sake not shown.

In Fig. 7 is a seventh embodiment of an inventive brake system ^¬ to a tandem master cylinder 3 in a coaxial arrangement to the second mechanical connection 9 is shown schematically. Travel simulator 2 comprises two Kol ^¬ ben-cylinder assemblies 2a, 2b, whose simulator piston 31a, 31b are actuated together by the first mechanical connection means 8, which comprises, correspondingly, two force deflections. The two piston-cylinder assemblies 2 a, 2 b are arranged symmetrically on opposite sides of the master cylinder 3. This results in a torque-free betae ^¬ actuation of the brake pedal 1 through the first mechanical connection Ver ^¬ 8 is possible. The brake system according to the seventh exemplary embodiment also includes one wheel brake 10 each, eg, los open, valve 18, which is used by means of the actuator 6 for brake pressure modulation in the multiplex process.

Fig. 8a) shows schematically a section of an eighth ^exemplary embodiment of a brake system according to the invention. Pressure ^¬ chamber 5 of the master cylinder 3 is connected by means of brake line 7 with hydraulically actuated wheel brakes 10. Pedal feel simulator 2 is designed hydraulically and comprises a cylinder-piston arrangement with a hydraulic chamber 32 which is connectable to the wheel brakes 10. According to the example, between the wheel brakes 10 (or their inlet valves 18) and the hydraulic chamber 32 ^λ an electrically controllable, eg normally open, separating valve 19 is arranged. By

Closing of the isolation valve 19 can pressure interactions of the wheel brakes 10 on the simulator 2 / the brake pedal 1 at a brake pressure modulation, such as in an ABS or vehicle dynamics control (by moving the actuator 6), are prevented. By opening the separating valve 19 or when the separating valve 19 is open, the brake pedal can be reset by means of the Fremdkraftaktuators 6 (by pressure build-up in Hauptbremszylin ^¬ of 3) if necessary.

As can be seen from FIG. 8 a), the pedal feel simulator 2 is additionally designed, for example, in such a way that the pressure feedback (for example from the wheel brakes 10) is reduced in a lower pressure range. To this end, comprises the Pe ^¬ dalgefühlsimulator 2 two different effective areas Al, A2, and optionally a spring 20. The hydraulic chamber 32 ^λ is of a first piston 21 with the effective area AI and the first piston 21 by cross-second piston delimits 31 with a smaller effective area A2, wherein Piston 31 is actuated by the first mechanical connection means 8 and is supported in the brake actuation direction via spring 20 on the piston 21. The operation of the pedal feeling simulator 2 is explained in the fol ^¬ constricting reference to the Fig. 8.

Upon actuation of the brake pedal 1 (with pedal force F) initially acts at small pedal travels s the smaller piston ^¬ area Ai of the second piston 31, resulting in displacement characteristic to a flat force, as shown in Fig. 8b in the region A. When spring 20 reaches the first piston 21, first the spring 20 is compressed, which leads to a more increasing force-displacement characteristic (area B in Fig. 8b), before piston 21 is displaced with its effective area A2, resulting in a still leads steeper increase in the force-displacement curve (area C in Fig. 8b).

The active surfaces AI, A2 of the travel simulator 2 are acted upon by the pressure of the wheel brakes 10 and by the structure of the simulator 2 (two offset effective piston surfaces AI, A2 different size, slow transition by spring 20), the pressure feedback is reduced in a lower pressure range ( so-called Springer function).

In Fig. 9, a ninth embodiment of a brake system according OF INVENTION ^¬ dung is shown schematically. The Wegsi ^¬ mulator 2 is designed in two stages, wherein the first stage is carried out according to the eighth embodiment. Path simulator 2 comprises a piston-cylinder arrangement with two successively arranged hydraulic chambers 32 ^λ and 26, which are separated by a floating piston. By means of the first mechanical connecting means 8 is piston betae ^¬ Untitled 31st Each of the hydraulic chambers 32 26 of the travel simulator 2 is connected to a brake circuit I, II with two wheel brakes 10, wherein each wheel brake is connected upstream of a normally open valve 18 for braking pressure modulation. Per brake circuit I, II is a normally open isolation valve 19 for Verhinde ^¬ tion of pressure interactions in a brake pressure modulation between the hydraulic chamber 32 and 26 wheel brakes 10 arranged. Master cylinder 3 is designed as a tandem master cylinder in dissolved construction, the primary piston and the floating piston circuit are each formed by two cylinder-piston assemblies 3a and 3b, the torque-free force introduction by the actuator 6 symmetric to the axis of the first mechanical connection 8 are arranged (on opposite longitudinal sides of the path simulator 2). To the primary piston circuit of the tandem master cylinder 3 brake circuit I with two wheel brakes 10 and to the floating piston circuit brake circuit II with two Radbrem ^¬ sen 10 is connected. The two cylinder-piston assemblies 3b of the floating piston circuit are rotated by 90 degrees relative to the two cylinder-piston assemblies 3a of the primary piston circuit arranged, so that only the primary piston circuit in Fig. 9 is shown.

According to the ninth embodiment, the displacement simulator 2 is used as a filling device (principle of the volume amplifier). For this purpose, the hydraulic space 32 ^{λ of} the path simulator 2 with the brake circuit I and thus the corresponding wheel brakes 10 is connected. Furthermore, the hydraulic chamber 32 ^{λ is} connected to a low-pressure accumulator 14 via an electrically controllable, eg normally closed, valve 15. The bias of the spring of the low-pressure accumulator 14 limits the filling pressure.

According to the example, the sensor device 34, which the defined for ^¬ stand of the travel simulator 2 as a displacement sensor 34 is for sensing the position / displacement of the piston 31 of the travel simulator 2 or related component ^¬ out. Furthermore, the brake system comprises, for example, a NEN pressure sensor 22 for measuring the pressure of the primary piston circuit.

9, the hydraulic components of the brake system, in particular travel simulator 2, master cylinder 3 and the valves 15, 18, 19, and optio ^¬ nal also the sensor devices, such as sensor devices 34, 22, advantageously in a housing 23rd arranged. Housing 23 can be easily arranged on the brake pedal 1 side facing away from the drive device 6. Only the two mechanical connecting means 8 and 9 thus extend from the housing of the drive device 6 to the housing 23.

As already described above, the travel simulator 2 is advantageously connected to the wheel brakes 10 via one or more normally open isolation valves 19 (see FIGS. 8 and 9). In a regenerative braking, the multiplex valves 18 are closed to prevent pressure build-up in the wheel brakes 10. At low pressures, the volume displaced by the driver in the travel simulator 2 is discharged via valve 15 into a low-pressure accumulator 14. At high pressures, the back pressure in the travel simulator 2 is simulated by suitable activation of the actuator 6.

In Fig. 10 a tenth embodiment of an inventive brake system ^{¬ is} shown schematically. This from ^¬ leadership example largely corresponds to the seventh exporting ^¬ approximate example. In addition to the normally open valves 18 in the brake lines to the wheel brakes 10, which are used for brake pressure modulation, the brake system additionally comprises one or more, eg all, wheel brake circuits electrically controllable, eg normally closed, valves 24, by means of which a connection to a low Pressure level 25 (Pressure medium reservoir (atmospheric pressure) or low pressure accumulator) can be produced. According to the example, two of the wheel brakes 10 are additionally connectable via valves 24 with a low pressure level 25, whereby a rapid brake pressure reduction in these wheel brakes is possible. In this way there is a possibility available, the rate of brake pressure modulation ^¬ in case of simultaneous demand of a pressure reduction at a wheel brake and a pressure build-up at ei ^¬ ner different wheel brake to improve.

The electrically controllable electromechanical Antriebsvorrich ^¬ tion 6 of the embodiments includes, for example, a Elektromo ^¬ tor and a rotational-translation gear, such as a Ku ^¬ gelgewindetrieb, for converting a rotational movement of the electric motor in a linear motion. Advantageously, the drive device 6 is arranged in a housing, wherein the first mechanical connection means 8 the housing ^¬ through erstrecht.

Advantageously, a brake system according to the invention comprises a sensor device 34 for detecting the state of the travel simulator 2, eg for detecting the position of a component of the travel simulator (eg a piston 31) or for detecting the position / position of the first mechanical connection means 8, as well as a sensor device 35 for detecting the state of the master cylinder 3, for example for detecting the position / position of a piston 4 of the master cylinder 3 or the position / position of the second mechanical connection means 9 or the position / position of a component of the actuator 6 (eg the rotor position of the electric motor or the location of a spindle of a rotation-translation gear). Additionally or alternatively, a brake system according to the invention advantageously comprises a sensor device 22 for detecting a pressure in the master cylinder 3 and / or in a wheel brake 10 and / or a sensor device for detecting a pressure in the travel simulator 2.

Claims

Claims:

1. brake system for motor vehicles with

A brake pedal (1),

• a travel simulator (2) which via an actuating force transmitting first mechanical Ver ^¬ binding agent (8) with the brake pedal (1) is coupled,

A master cylinder (3) having at least one pressure chamber (5) and a piston (4), the pressure chamber (5) of which is connected or connectable to at least one hydraulically actuated wheel brake (10) via a pressure line (7), and

• an electrically controllable electromechanical

Drive device (6), with which the piston (4) of the master cylinder (3) via a second mecha ^¬ African connection means (9) is actuated, characterized in that the electromechanical Ant ^¬ rubbing device (6) between

• the brake pedal (1) on the one hand and

• the master cylinder (3) and the travel simulator (2) on the other

is arranged, wherein the first mechanical connec ^¬ tion means (8) of the brake pedal (1) through the Ant ^¬ rubbing device (6) extends through to the path simulator (2).

2. Brake system according to claim 1, characterized in that one of the mechanical connection means (9), in ^¬ particular the second mechanical connection means, ^{¬ at} least partially formed as a hollow body, and that the other mechanical connection means (8), in particular the first mechanical fasteners, at least partially disposed within the hollow body.

3. Brake system according to claim 1 or 2, characterized in that the path simulator (2) comprises at least one piston-cylinder arrangement, the simulator piston (31) with the first mechanical connection means (8) is connected, wherein the simulator piston (31) in particular a hydraulic space (32 ^λ ) limited.

4. Brake system according to claim 3, characterized in that the hydraulic space (32 ^λ ) with at least one wheel brake (10) is connected or connectable.

5. Brake system according to claim 3 or 4, characterized in that the hydraulic space (32 ^λ ) via a elekt ^¬ rically controllable valve (16,) with a low ^¬ pressure accumulator (14) is connected.

6. Brake system according to one of claims 3 to 5, characterized in that the displacement simulator (2) in addition to the simulator piston (31) comprises a further piston (21) and a spring (20), wherein the simulator piston (31) has a smaller piston effective area (AI) as the further Kol ^¬ ben (A2) possess, in which further piston (21) is guided displaceably and by means of the spring (20) on the further piston (21) is supported.

7. Brake system according to claim one of claims 3 to 6, characterized in that between the hydraulic space (32 ^λ ) of the travel simulator (2) and the wheel brake (10) an electrically controllable, normally open release valve (19) is arranged.

8. Brake system according to one of claims 3 to 5, characterized in that the hydraulic space (32 ^λ ) via a check valve (17) to the master cylinder (3) is connected, which is connected to at least one wheel brake (10).

9. Brake system according to one of claims 1 to 8, characterized in that the displacement simulator (2), in particular the piston-cylinder arrangement of the travel simulator (2), and the master cylinder (3) are arranged substantially parallel to each other, and that at least comprises ers ^¬ te or the second mechanical connection means (8, 9) for transmitting force.

10. Brake system according to one of claims 1 to 9, characterized in that the first (8) and the second (9) mechanical connection means are formed (11, 12) that an actuation of the master cylinder (3) in the brake actuation direction by means of the first mechanical connection means (8) by a mechanical ^¬ rule contact (12) between the first mechanical connecting means (8) and the master brake cylinder (3) or the first mechanical connecting means (8, 11) and the second mechanical connection means (9) is possible.

11. Brake system according to one of claims 1 to 10, characterized in that it comprises at least one Sensorvorrich ^¬ device (34, 35), by means of which the relative position of the first (8) to second (9) mechanical connection means is determined.

12. Brake system according to one of claims 1 to 11, characterized in that the pressure chamber (5) of the Hauptbremszy- Linders (3) via an electrically controllable valve (15) with a pressure medium container (14) is connectable.

13. Brake system according to one of claims 1 to 12, characterized in that the second mechanical connection ^¬ medium (9) in such a way, in particular in two parts, is formed, or the coupling between the piston (4) of the

Main brake cylinder (3) and the second mechanical connection means (9) in such a way, in particular releasably, out ^¬ leads is that the piston (4) of the master cylinder (3) by means of the first mechanical connection means

(8) is operable, even if the drive device (6) is blocked.

14. Brake system according to one of claims 1 to 13, characterized in that the first mechanical connection ^¬ medium (8) and the second mechanical connection means

Along a predetermined path (13) (9) are designed such that the second mechanical connection means (9) by the drive device (6) can be adjusted in braking actuation ^¬ direction relative to the first mechanical connection ^¬ medium (8) without a Mitnah ^¬ me or reaction to the brake pedal (1) takes place.